Esters of amidoxalic acid



under reaction conditions.

United States Patent 3,317,584 ESTERS 0F AMIDOXALIC ACID 1 Paul J. Stolfel, St. Louis, Mo., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware N0 Drawing. 4 v p 6 Claims. (Cl. 260-465) This invention relates to a procedure for preparing a family of esters of oxalamides. The purpose of the invention is to provide a new procedure for preparing com-- pounds.

More specifically, the purpose of this invention is to provide compounds of the formula wherein R and R are both hydrocarbon radicals selected from the class consisting of alkyl having up to 12 carbon atoms, alkenyl having up to 12 carbon atoms, alkynyl of up to 12 carbonatoms, cycloalkyl having from 4 to- 7 carbon atoms, benzyl, phenyl, naphthyl, and cycloalkenyl of four to six carbon atoms; and the said hydrocarbonradicals having substituents selected from the class consisting of chlorine, bromine, nitro, cyano, alkyl of up to four carbon atoms, alkoxy of up to four carbon atoms, alkenyl of up to four carbon atoms, alkenoxy of upto four carbon atoms, alkynyl of up to four carbon atoms and alkynoxy of up to four carbon atoms.

The procedure involves the reaction of cyclic anhydrides' with alcohols or phenols in accordance with the equation:

Filed Mar. 13, 1964, Ser. No. 3 1 ,827

'- methanol.

3,3 1 7 ,5 84 Patented May 2, 1967 EXAMPLE 1 Methyl 3,4-dichl0r0xanilate EXAMPLE 2 Ethyl N-propynyloxamate '7 I 'Tl'ie procedure of the above example was repeated using I These cyclic anhydn'des, otherwise identified as N-snbstituted oxazolidinetriones, are described and claimed in application Serial No. 310,854, filed September 9, 1963, by Paul J. Stoifel, which application also includes a disclosure of useful methods for their preparation. This application has now issued as US. Patent 3,264,317. The R OH may be alcohols such as methanol, cyclohexanol, benzyl alcohol, decyl alcohol and any other organic compound containing a hydroxyl group on an aliphatic carbon atom. Alternatively, the R OH may be a phenolic compound, such as phenol, naphthol and other organic compounds having a hydroxyl group attached to a benzenoid carbonatom.

The reaction between oxazolidinetriones and the said hydroxy compounds (R OH) is effected by contacting the reagents dissolved in an excess of the alcohol or phenol. The reaction is exothermic and no additional heating is required. The reaction is spontaneous and carbon dioxide is evolved. The action may become too vigorous and gradual addition of the oxazolidinetrione to a large excess of the organic hydroxy compound may become advisable. A cooled reactor or a cold reflux condenser may be used to keep the reaction under control. When the reaction is complete, the product may be precipitated By cooling, a high yield of the desired product is recovered in crystalline form.

The product may be purified by dissolution in a suitable solvent, for example the alcohol or phenol from which it is synthesized. Upon cooling, the product is crystallized in pure form.

3-allyloxazolidinetrione and ethyl alcohol as the reactants. The resulting product was found to have the structure:

CHFOHCH2NHil -O CzHn EXAMPLE 3 Isopropyl N-cyclohexyloxamate By reacting 3-cyolohexylazolidinetrione with an excess of isopropanol with gradual intermixing the reagents, a

, product of the following structure was recovered:

Doziecyl N-benzyloxamate 3-benzyloxazolidinetrione was mixed with an excess of n-dodecyl alcohol at an ambient temperature for three hours. The reaction mixture was cooled and a solid product precipitated. The crystalline product was identified as having the structure? W E Q-OHa-NH-C- o(oHi noH3' EXAMPLE 5 t-But'yl N-cyclopentadienyloxamate A product was made by condensing 3-cyclopentadienyloxazolidinetrione with t-butyl alcohol in an excess .of the alcohol. The reaction was effected at a temperature maintained below 50 C. Upon cooling a crystalline-product was formed which was found to have the structure:

Methyl p-methoxyoxanilate 3(p-methoxyphenyl)oxazolidinetrione was reacted with an excess of methanol by charging a flask with the methanol and gradually adding thereto the other reactant at a rate such that the reaction was maintained under control. A compound of the following formula was recovered from the reaction mixture:

EXAMPLE 7 RFNH C C ORI II II n-Octyl 3,4-dichlr00xamlate 0 Using the procedure of Example 5, 3(2,4-dichlorophcnformed.

Phenols N-Substituted Oxamates M.P., C.

Y r i Y 3,5dimethylphen0l. cPn-NH-c-o o 124. 1424.- s

i 1 3,4-diehlorophenol cH=-NH-o-h-oo1 116.1ll6.7

o o I CH; 4-chloro-3,5-dlmethyl- CH;-NH-GCO 01 15s. 1-158. 6

phenol.

9 i ON 3-cyanophenol CH3NHCC-O 132.9133.5 if R 4-methoxyphenol cm-NH-c-o-00cm 130-131 fl-Naphthol CH;NH-C-C-O 1l5.6-1l6.2

H l 69.1-10.5 4-t-butyl-2-methylphenol CH3-NHC O yloxazolidinetrione was reacted with n-octanol to pro- EXAMPLE 17 duce a compound of the formula EXAMPLE 8 Methyl p-nitrooxanilate By using the procedure of Example and replacing the oxazolidinetrione with p-nitrophenyloxazolidinetrione a compound of the following formula was recovered from the reaction mixture:

0 OMQNH-(i-iLOCH EXAMPLE 9 A llyl N (4-br0m0-2-methylbenzyl oxamate The reaction between 2-methyl-4-bromobenzyloxazolidinetrione and allyl alcohol produced a compound identified as that of the formula EXAMPLES 10 THROUGH 16 Compounds were prepared by reacting 3-methyloxazolidinetrione with each of the phenols identified by the following table; The table also discloses the ester formed and then the physical properties The reaction between p-nitrophenol and 3-allyloxazo1idinetrione produced a crystallized product of the structure:

By the specifically described procedures, N-substituted oxazolidinetriones were reacted with selected alcohols and phenols to prepare the following:

Cyclohexyl p-allyloxyoxanilate Naphthyl N-cyanobenzyloxamate Propargyloxymethyl N-naphthyloxamate Benzyl p-propargyloxanilate Allyl N-(3-methoxypropyl)oxamate p-Nitrophenyl N-cyclopentadienyloxamate o-Bromo-p-methoxybenzyl N-allylbenzyloxamate p-Allyloxyphenyl p-methoxyanilate 00 H II 5 6 wherein R is alkyl of up to 12 carbon atoms, which com- 4. The method of preparing cyanophenyl N-methylprises contacting the oxazolidinetrione of the formula oxamate which comprises contacting 3-cyanophenol with 3-methyloxazo1idinetrione with a large excess of 3-cyano- N H phenol. T 5 5. The method of preparing p-methoxyphenyl N- I 0 methyloxamate which comprises contacting 3-methyloxazolidinetrione with a large excess of p-methoxyphenol. I; ll 6. The method of preparing methyl p-rnethoxyoxanilate which comprises contacting 3(p-methoxyphenyDoxazoli- With an alkyl alcohol of P to 12 Carbon atoms- 10 dinetrione withalarge excess of methanol.

2. The method of preparing methyl 3,4-dichlorooxan1- I late which comprises reacting 3-(3',4'-dichlorophenyl) No references cited.

oxazolidinetrione with an excess of methanol.

3. The method of preparing 3,4-dichlorophenyl N- CHARLES B. PARKER, Primary Examiner.

methyloxamate which comprises reacting 3-methyloxa- 15 D'HTORRENCE Assistant Examiner. zolidinetrione with an excess of 3,4-dichlorophenol. 

1. THE METHOD OF PREPARING COMPOUNDS OF THE STRUCTURE: 